1. Field of the Invention
The present invention relates to a technique for generating track information that indicates the track of a vehicle.
2. Description of the Related Art
In an existing art, there is known a technique that acquires an estimated current position of a vehicle through self-contained navigation based on the results detected by a direction sensor and a distance sensor. For example, Japanese Patent Application Publication No. 2000-298028 (JP-A-2000-298028) describes a technique in which an estimated current position of a vehicle is acquired on the basis of the results detected by a direction sensor and a distance sensor, the estimated current position is compared with candidate positions on a road to determine the most probable candidate position on the road and then the estimated current position is corrected on the basis of the most probable candidate position on the road. In addition, JP-A-2000-298028 describes a technique for determining an error circle to narrow candidate positions on a road on the basis of an estimated current position and a position measured by a GPS.